Strange, I have tried to revert to the original src-directory and tried "Rescan fpc source directory" - but then i cannot get definitions, when I CTRL-mouseclick on a procedure from jwaWindows.
When I change back to the source directory with the cases changed, It works immidialty - without rerunning "Rescan fpc source directory". For me, it is not a problem, since I can get it working in my env. Thank you for your suggestions.